Diagnostic accuracy of post-mortem MRI for thoracic abnormalities in fetuses and children

Abstract

ObjectivesTo compare the diagnostic accuracy of post-mortem magnetic resonance imaging (PMMR) specifically for non-cardiac thoracic pathology in fetuses and children, compared with conventional autopsy.MethodsInstitutional ethics approval and parental consent was obtained. A total of 400 unselected fetuses and children underwent PMMR before conventional autopsy, reported blinded to the other dataset.ResultsOf 400 non-cardiac thoracic abnormalities, 113 (28 %) were found at autopsy. Overall sensitivity and specificity (95 % confidence interval) of PMMR for any thoracic pathology was poor at 39.6 % (31.0, 48.9) and 85.5 % (80.7, 89.2) respectively, with positive predictive value (PPV) 53.7 % (42.9, 64.0) and negative predictive value (NPV) 77.0 % (71.8, 81.4). Overall agreement was 71.8 % (67.1, 76.2). PMMR was most sensitive at detecting anatomical abnormalities, including pleural effusions and lung or thoracic hypoplasia, but particularly poor at detecting infection.ConclusionsPMMR currently has relatively poor diagnostic detection rates for the commonest intra-thoracic pathologies identified at autopsy in fetuses and children, including respiratory tract infection and diffuse alveolar haemorrhage. The reasonable NPV suggests that normal thoracic appearances at PMMR exclude the majority of important thoracic lesions at autopsy, and so could be useful in the context of minimally invasive autopsy for detecting non-cardiac thoracic abnormalities.Key Points• PMMR has relatively poor diagnostic detection rates for common intrathoracic pathology• The moderate NPV suggests that normal PMMR appearances exclude most important abnormalities• Lung sampling at autopsy remains the “gold standard” for pulmonary pathology

Perinatal death investigations: What is current practice?

“…PMMRI is of value in detection of cardiac pathology, with an overall sensitivity of 73% and specificity of 96% for any cardiac pathology, being more accurate for major structural heart disease (sensitivity 93%, specificity 99%) [85]. PMMRI is not accurate in detecting other intrathoracic pathologies such as infection or hemorrhage (overall sensitivity 40% and specificity 86%), but it is useful for detection of anatomical abnormalities, such as pleural infusions and lung or thoracic hypoplasia [86]. PMMRI detects abdominal pathology accurately (overall sensitivity 73%, specificity 91%); it is especially good at detecting renal abnormalities, but relatively poor at detecting intestinal abnormalities [87].…”

Alternatives to Autopsy for Fetal and Early Neonatal (Perinatal) Deaths: Insights from the Wisconsin Stillbirth Service Program

“…Although the literature shows good results for fetal virtual autopsy using MRI and ultrasound, several factors in addition to cost and insurance considerations limit the feasibility of widespread implementation: first, high field MRI is not widely available and access to MRI for postmortem cases is likely to be limited because most pathologists are dependent on hospital‐based clinical MRIs and must compete for use with living patients. Second, reading postmortem imaging requires substantial training, particularly with respect to understanding normal postmortem changes (Arthurs et al, a, b; Whitby et al, ; Ashwin et al, ). Thus, minimally invasive autopsy protocols primarily based on postmortem imaging are unable to be immediately implemented by clinicians seeking to investigate a perinatal death and are unlikely to become widely available in the near future.…”

Is there still a role for fetal and perinatal post-mortem radiography?

“…However, overall sensitivity of post-mortem MRI for musculoskeletal abnormalities was poorer, and in the evaluation of skeletal abnormalities such as skeletal dysplasias is best used in conjunction with plain radiographs [40].…”